In the past, a fast solution is to utilize a metal threaded plug or nipple cap to block the exit pipe in a sprinkler system. That only seals the exit pipe while workers work around the sprinkler system. Ma, U.S. Pat. No. 7,624,813, shows the use of this metal plug and a hole in a drywall having a metal ring. This however introduces inaccurate placement and dimensioning of the hole relative to the sprinkler system that sometimes workers have to redo the hole and reinstall drywall. Also, when painters come around, the painters paint over the metal ring which bonds the metal ring to the drywall thus not making it aesthetically to the eye.